rGO decorated ZnO/CdO heterojunction as a photoanode for photoelectrochemical water splitting

Lixia Sun; Jianhua Sun; Xi Sun; Shouli Bai; Yingying Zhao; Ruixian Luo; Dianqing Li; Aifan Chen

doi:10.1016/j.jcis.2021.10.140

rGO decorated ZnO/CdO heterojunction as a photoanode for photoelectrochemical water splitting

J Colloid Interface Sci. 2022 Feb 15;608(Pt 3):2377-2386. doi: 10.1016/j.jcis.2021.10.140. Epub 2021 Oct 28.

Authors

Lixia Sun¹, Jianhua Sun², Xi Sun³, Shouli Bai³, Yingying Zhao³, Ruixian Luo³, Dianqing Li⁴, Aifan Chen³

Affiliations

¹ Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China.
² Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China; Center on Nanoenergy Research, School of Physical Science and Technology, Guangxi University, Nanning 530004, China. Electronic address: sunjhgx@gxu.edu.cn.
³ State Key Laboratory of Chemical Resource Engineering, Beijing Key Laboratory of Environmentally Harmful Chemicals Analysis, Beijing University of Chemical Technology, Beijing 100029, China.
⁴ State Key Laboratory of Chemical Resource Engineering, Beijing Key Laboratory of Environmentally Harmful Chemicals Analysis, Beijing University of Chemical Technology, Beijing 100029, China. Electronic address: lidq@mail.buct.edu.cn.

PMID: 34774314
DOI: 10.1016/j.jcis.2021.10.140

Abstract

A ternary photoanode of ZnO/CdO heterojunction decorated with reduced graphene oxide (rGO) was firstly fabricated by electrochemical deposition and thermal decomposition that is simple and effective compared with other method reported in literature. The structure and morphology of the photoanode were systematically characterized by various spectrum technologies. The photoanode expands the visible light absorption range to 428 nm, the photocurrent density reaches 1.15 mA·cm^-2 at 1.23 V (vs. RHE) that is 3 times and 1.85 times of pure ZnO (0.38 mA·cm²) and ZnO/CdO (0.62 mA·cm²) photoanodes. The highest IPCE value reaches 42.63% at 380 nm. The enhancement is attributed to the architecture of semiconductor heterojunctions and the decoration of rGO nanosheets, the former promotes charge separation, while the latter accelerates electron transfer thus both synergistically enhance PEC water splitting efficiency. Here fabricated photoanode has never been reported before, only Cd and other metal elements doped ZnO photoanodes were reported in the literature.

Keywords: CdO; Photoelectrochemical water splitting; Reduced graphene oxide; Semiconductor heterojunction; ZnO.